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This study investigates the aerodynamic performance of different flying sensors inspired by dandelion seeds, using COMSOL Multiphysics CFD simulation. Dandelion seeds are well known for their ability to remain suspended in the air for extended periods due to their lightweight structure, higher porosity, high drag, and the formation of a separated vortex ring (SVR) above the seed. Mimicking this behavior, five 2D and one 3D geometry were developed and analyzed first through steady-state simulations to explore how different design geometries influence passive flight performance. The primary aim is to identify an optimized structure that can achieve slower descent when realized from an altitude by drones for remote sensing. Steady-state results showed that although the drag coefficient generally decreased with increase in Reynolds numbers, porosity did not exhibit a constant trend across all designs. In some cases, geometries with lower porosity outperformed more porous ones. This may be due to their structural differences. SVR was observed in all designs. However, the distance between these SVR and geometry’s surface was small. While steady-state results give a fair indication of the aerodynamic behavior and relative performances of the various geometries, there are limitations. To address this, transient drop tests, currently under verification, will give a better understanding of the performances of these designs from which the best will be selected. 

This study aimed to investigate the aerodynamic and thermal behavior of dandelion diaspore analogs to explore the effect of coloration on the overall flow field. To do so, computational fluid dynamics simulations were performed on simplified porous disk models across varying absorptivities under steady-state and transient conditions. By coupling heat transfer and fluid dynamics, the simulations captured the influence of thermal gradients on stable vortex ring formation and overall drag forces. Results showed that increased surface temperature, caused by higher absorptivity, enhanced buoyancy forces, disrupted vortex ring formation, and elevated drag coefficients. Conversely, white-colored analogs exhibited lower thermal loading and reduced aerodynamic resistance. While the current model employed a rigid, porous disk approximation, it provides valuable insights into the effects on the fluid flow of unmanned, dandelion-inspired micro aerial vehicles (MAVs).